A monitoring system in which a plurality of cameras are installed in a monitoring area and a monitoring screen for displaying a video from each of the plurality of cameras is displayed on a monitor so as to be monitored by a monitoring person has been widely spread. In such a monitoring system, a monitoring person can check what types of actions a person, who performed a problematic action such as shoplifting, performs in the monitoring area, by accumulating the videos from the cameras in a recorder.
In this way, in a case where a monitoring person tracks a person while viewing the monitoring screen, as the person moves in the monitoring area, the cameras which capture the image of the person are switched one by one, so that it is required to sequentially check the video from each of the cameras.
Thus, a technique of providing a video display window for displaying a video from each camera on the display screen of the monitor, displaying the video of the person designated by the monitoring person as the tracking target in the video display window, and the traveling route of the person on the display screen of the monitor has been known (see PTL 1). In this technique, since the traveling route is displayed, it is possible to relatively easily perform a tracking work while changing cameras one by one, thereby reducing to a certain extent of the burden on the monitoring person who performs the tracking work.